Patent GB-451795-A (GB)
Title: Improvements in speed control gear for motor vehicles
IPC: B60K31/02
Filed: 1935-03-21
Abstract: 451,795. Speed governors; engine stop-gear. HULME, W., 24, Sundial Road, Offerton, Stockport, HULME, L., 241, Kingsway, Manchester, and STAMP, N. H., 14, Roslyn Road, Davenport, Stockport. March 21, 1935, No. 8824. [Classes 57 and 122 (iv)] [See also Group XXXI] In automatic control gear the rods or levers controlling the throttle valve of a steam or internal-combustion engine are made in two parts connected together by trip mechanism which is operated by a solenoid to release the throttle valve and allow it to close when the vehicle attains a predetermined speed, the solenoid circuit being completed by a moving member of a governor or speedometer. In the construction shown in Fig. 1, the throttle is connected to a tubular rod C and the operating means to a rod C<1> sliding in the tube C. Normally, the parts C, C<1> are connected together by a trip lever A<1> pivoted at a<1> to C and having a catch a<5> engaging a notch c<1> in C<1>. A solenoid A is carried by a bracket a on the rod C, and when the finger B of a speedometer D indicates a predetermined speed of (say) 30 miles per hour, the armature A<2> is operated and rocks the lever A<1> to release the catch as, so that the part C is free to move relatively to the part C<1> and the throttle is closed by its spring, a spring C<2> being compressed as the tube C' slides over the rod C. When the driver releases the pressure on the rod C<1> the spring C<2> withdraws the rod from the tube until the catch a<5> can spring into its notch and the rod and tube are coupled together again if the speed has fallen below 30. A construction of governor or speedometer apparatus is shown in Fig. 3 and comprises a shaft d<1> driven by a shaft d at a speed corresponding to the vehicle speed, and a constant speed shaft d<7> driven from the shaft d through a slipping clutch d<8> and controlled by an escapement d9, d<13>. The shaft d<1> is movably mounted on a lever d3 controlled by a cam d'O on the shaft d<7> so that at regular time intervals a pinion d<2> on shaft d<1> is engaged with and disengaged from a gear-wheel d4 loose on a shaft d<6> carrying a pointer B<1>. The gear d<7> is adapted to rotate a gear d<5>, fixed on the shaft d<6>, by means of two pins d<16>, d<17>. The gears d<4>, d<5> tend to return to zero position under the influence of springs d<21>, d<22> and are held in their forward positions by pawls d<15>, d<14> controlled by cams d<12>, d<11> on the shaft d<7>. When the gear d<4> is engaged by pinion d<2> it is driven for a definite time period and thus rotates through an angle determined by the speed at which it is driven. By means of the pins d<16>, d<17> it carries the gear d<5> with it; when the gear d<4> is disengaged from the pinion it flies back to zero under the control of its spring d<21> and is held by pawl d<15>, but the gear d<5> is held by its pawl d<14> in the advanced position corresponding to the speed of shaft d. During the next engagement of the pinion with the gear d<4>, if the speed is the same the pin d's moves up to the pin d<17> and keeps the gear d<5> and pointer B' in position ; if the speed has increased the gear d<4> moves farther and carries the gear d<5> to an advanced position ; whereas if the speed has decreased the gear d<5> moves back, under the influence of its spring d<22> when it is released, until the pin d<17> engages the pin d<16> in a lower speed position. For use as a governor only, a pin d<18> is provided on the gear d<5> to limit its return movement, and a part of the gear d4 is cut away at d<19> so that the pointer B<1> does not move beyond a predetermined limit position should the vehicle exceed the limit speed with the throttle valve closed.